The race for bendy tech

The race to make bendable technologies is on, with scientists already dreaming of unbreakable mobile phones, glowing running shirts, and self-measuring food labels. But a few final hurdles are holding back the rush to market, as Wendy Zukerman discovered at one of the premier bendy tech labs.

Have you ever felt that sinking feeling as you dropped your smart phone, then watched in horror as its sleek glass screen shattered on the pavement?

Never fear, as across the globe, researchers are racing to develop a phone that is virtually unsmashable. This hardy device could also bend, roll and even be transparent. More remarkable still, the next generation phone could be printed, making it potentially very cheap.

And the technology that will build this bendy phone could change more than just communication tools. Flexible electronics are set to revolutionise medicine, fashion, advertising, industrial design and even the way we cook.

Scientists are proposing to pack smart, flexible tissues with biosensors capable of diagnosing sniffles. Favourite running T-shirts could be embedded with light emitting materials, helping joggers run safely at night. Rooftops could be transparent.

Before flexible phones reach our stores and get squished into our pockets, scientists must find bendable materials that can protect the display and circuitry from dust and moisture, as well as the mechanical stresses of bending and folding. Professor Vellaisamy calls it 'the encapsulation problem'.

And that tub of chocolate ice cream? The label could be cheaply printed with sensors that track how much has been eaten in one sitting. Large, flexible sheets dappled with motion-sensors could monitor the tiny vibrations on bridges and powerlines, sending automatic messages to maintenance workers when they need to be fixed.

Last week, researchers at the University of Tokyo in Japan unveiled an ultra-thin, ultra flexible foil, made of plastic and sprinkled with sensors. The team believe the device could be used to monitor heart rates, track temperature changes and even trap solar energy.

Creating flexible electronic devices involves harnessing a next generation of materials called OLEDs, which stands for Organic Light Emitting Diodes.

'Organic materials are either made from small molecules or polymers, so they are very flexible in nature,' says Associate Professor Roy Vellaisamy at City University of Hong Kong, who is developing the materials that will be used to make flexible electronics.

'This is the reason that people think OLED is the future and they spend a lot of money to try to make flexible displays. Just imagine a phone which is like a paper.'

Traditional LED screens are made from inorganic and inflexible materials, making them difficult to bend or print. 'It’s basically, mission impossible,' says Professor Vellaisamy.

Earlier this year, I visited Professor Vellaisamy’s team at the City University of Hong Kong in Kowloon. He guided me through a series of rooms, each working on different aspects of creating flexible electrical devices.

In one room, rumbling chambers delicately plop different organic materials onto very small displays. Later the team will test which materials will most efficiently provide light and colour for a flexible mobile phone display. Right now, the team are testing substances called blue fluorophors, which emit blue light, but can be engineered to glow green and red as well.

Professor Vellaisamy whisks me to another room, where the team produce larger OLED displays. He eagerly hands me a six centimetre by six centimetre piece of plastic. It looks like nothing more than a clothes tag, but is in fact the prototype of a flexible mobile phone display.

Many companies are racing to create the first bendable smart phone: Philips, Sharp, Nokia and Sony are all in the game. Last year, it was reported that South Korean phone manufacturer Samsung would have a phone with a flexible display ready by this year . Indeed, by January they unveiled a prototype of this bendy device

According to Professor Vellaisamy, before flexible phones reach our stores and get squished into our pockets, scientists must find bendable materials that can protect the display and circuitry from dust and moisture, as well as the mechanical stresses of bending and folding. Professor Vellaisamy calls it 'the encapsulation problem'. Right now, phones are encapsulated with rigid glass.

'You must have very good encapsulation, otherwise lifetime will go down dramatically,' he says.

And although a bendable display is pretty cool, for a completely flexible mobile phone, the display as well as the electronics underneath need to be malleable—that includes the battery, antenna, and everything else in the phone.

Professor Vellaisamy shows me where the team are producing flexible circuits. He hands me another small piece of plastic, the prototype of a thin film transistor. It’s the device that will switch each pixel on the OLED display 'on' and 'off'.

'This is one of the circuits, completely on plastic,' he says. He also shows me a bendy flash memory device; a small plastic sheet capable of storing data.

In the corner of one room I spot a small doll's house, which looks remarkably out of place in this high-tech facility. I kneel down to peer in, and Vellaisamy’s colleague, Dr Roy Fung, points at the bottles of beer in the tiny house. This is a pub, he explains.

Dr Fung flicks a switch, and the ceiling becomes translucent. The roof of this house is also made of OLED light.

'The transparency is up to 80 per cent,' smiles Dr Fung. That’s another advantage of OLEDs—they can be made see-through. 'This cannot be done with inorganic LEDs, you never imagine transparency,' says Professor Vellaisamy.

Traditionally electrodes are a silver colour. So to make a transparent OLED, the team had to develop a translucent electrode.

An electrode is made of an anode and a cathode. In conventional electronics, anodes are made of Indium tin oxide (ITO), which is transparent, but the cathode is the silver-coloured aluminium. Instead, Dr Fung and Professor Vellaisamy replaced the opaque cathode with the transparent rare earth metals ytterbium and samarium. 'So the transparency is very good,' says Fung.

I marvel at the world’s most technologically advanced pub for dolls, and a future that's going to be fun, and flexible.